Improvement in boiler-flue scrapers



Patented Sept. 22,1874.

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fusses bodying my invention.

UNITED STATES PATENT OEEIGEo JOHN GOLLIOOTT, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN BOlLER-FLE SCRAPERS.

Specification forming part of Letters Patent No. 155,293, dated September 22, 1874; application tiled March 14, 1874.

To all 'whom t may concern:

Be it known that I, JOHN GoLLIcoTT, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Boiler-Tube Scrapers, of which the following, when taken in connection with the accompanying drawings, is a full, clear, and exact specication.

In this invention, the springs which spread the arms into the proper shape and position are protected from the heat, and thus prevented from being injuriously affected thereby, by being placed in a chambered or hollow hub constructed for `the purpose, which also holds the arms. Additional protection is aiorded by means of a partition cast in the mouth of the said hub. A metallic ring, encircling the arms, and held in place by a notch cut out in each, prevents the said arms from spreading too much.

In the accompanying drawings, Figure l represents an elevation of a tube-scraper em- Fig. 2 is a longitudinal section of the same, one of the arms havingbeen removed. Fig. 2 is a cross-section cut through the line w x, the arms having been removed.

Similar letters of reference indicate corresponding part-s.

a a are the arms, upon which are the scraping-edges. They are attached to the hollow hub by means of pins c c. b shows the chamberin the hub b. Attached atits upper end, by means of rivets or other devices, to each arm a is a spring, d. This spring d extends down through the chamber b', and, bending back into the shape shown in Fig. 2, presses against the side of the chamber. A very small portion only touches the hub, in order that the spring may not become heated. These four springs d serve to spread the arms a, and keep them firmly apart. e c show that portion of the hub in which the arms a rest.

In order to more perfectly protect the springs d in the chamber b from the heat, a partition,

g, is cast at the mouth of the chamber, thus making it nearly tight.

The arms a are kept from flying apart by the ring h, which lies in the notches k cut for the purpose in the arms.

Thus i-t will be seen that all danger of the annealing or improper heating of the springs d is obviated, and the great cause of the destruction of tube-Scrapers workin g with springs is entirely done away with.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

The chambered. or hollow hub b b', the said chamber being closed by means of the partition g, in order to prevent undue heat from affecting the springs d, substantially as herein specitied.

JOHN OOLLIOOTT.

Witnesses:

HENRY W. WILLIAMS, G. V. THAYER. 

